; (function (window, document) {
  var docEl = document.documentElement
  var dpr = window.devicePixelRatio || 1

  //adjust body font size
  function setBodyFontSize() {
    if (document.body) {
      document.body.style.fontSize = (12 * dpr) + 'px'
    } else {
      document.addEventListener('DOMContentLoaded', setBodyFontSize)
    }
  }
  setBodyFontSize();
  function setRemUnit() {

    var rem = docEl.clientWidth / 10;
    docEl.style.fontSize = rem + 'px';
    console.log("docEl.style.fontSize==>",docEl.style.fontSize);
  }
  setRemUnit();
  window.addEventListener('resize',setRemUnit)
  window.addEventListener('pageshow',function(e){
    if(e.persisted){
      setRemUnit();
    }
  })
  if(dpr>=2){
    var fakeBody = document.createElement('body')
    var testElement = document.createElement('div');
    testElement.style.border = '.5px solid transparent'
    fakeBody.appendChild(testElement);
    docEl.appendChild(fakeBody);
    if(testElement.offsetHeight === 1){
      docEl.classList.add('hairlines');
    }
    docEl.removeChild(fakeBody);
  }
})(window, document)